/Engine/Source/Runtime/Core/Public/Misc/ExpressionParserTypes.h
A node in an expression. Can be constructed from any C++ type that has a corresponding DEFINE_EXPRESSION_NODE_TYPE. Evaluation behaviour (unary/binary operator etc) is defined in the expression grammar, rather than the type itself.
class FExpressionNode : private [FNoncopyable](API\Runtime\Core\Templates\FNoncopyable)